Organic compound and organic thin film and electronic device

ABSTRACT

An organic compound is represented by Chemical Formula 1, and an organic thin film, a thin film transistor, and an electronic device includes the organic compound.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefits of Korean PatentApplication No. 10-2015-0087513 filed in the Korean IntellectualProperty Office on Jun. 19, 2015, and Korean Patent Application No.10-2016-0061613 filed in the Korean Intellectual Property Office on May19, 2016, the entire contents of each of which are incorporated hereinby reference.

BACKGROUND

1. Field

Example embodiments relate to an organic compound, an organic thin film,and an electronic device.

2. Description of the Related Art

A flat panel display (e.g., a liquid crystal display (LCD), an organiclight emitting diode (OLED) display, and/or an electrophoretic display)includes a pair of electric field-generating electrodes and anelectrical optical active layer interposed therebetween. The liquidcrystal display (LCD) includes a liquid crystal layer as an electricoptical active layer, and the organic light emitting diode (OLED)display includes an organic emission layer as an electrical opticalactive layer.

One of the pairs of the electric field-generating electrodes is commonlyconnected to a switching device and receives an electrical signal, andthe electrical optical active layer transforms the electrical signalinto an optical signal and thus displays an image.

A flat panel display includes a thin film transistor (TFT) that is athree-terminal element as a switch, a gate line that transmits a scansignal to control the thin film transistor, and a data line thattransmits a signal applied to a pixel electrode.

Research on an organic thin film transistor (OTFT) including an organicsemiconductor, e.g., a relatively low molecular weight semiconductor, orpolymer semiconductor instead of an inorganic semiconductor, e.g., asilicon (Si) semiconductor, as one type of thin film transistor is beingactively conducted.

The organic thin film transistor may be made into a fiber or a film dueto characteristics of an organic material, and thus is drawing attentionas a core element for a flexible display device. The organic thin filmtransistor may be made by a solution process, e.g., inkjet printing, andthus, may be more easily applied to relatively large area flat paneldisplay devices limited only by a deposition process.

SUMMARY

Example embodiments provide an organic compound that is applicable to anelectronic device, e.g., an organic thin film transistor.

Example embodiments also provide an organic thin film including theorganic compound.

Example embodiments also provide an electronic device including theorganic compound.

According to example embodiments, an organic compound is represented byChemical Formula 1.

In Chemical Formula 1,

each of A and B are independently one of a substituted or unsubstitutedC₆ to C₃₀ arylene group, a divalent substituted or unsubstituted C₂ toC₃₀ heterocyclic group, and a combination thereof,

each of Z¹ to Z⁶ are independently one of hydrogen, a C₁ to C₁₀haloalkyl group, and a halogen, provided that at least one of Z¹ to Z⁶is one of a C₁ to C₁₀ haloalkyl group and a halogen,

each of n¹ and n² are independently an integer of 0 to 5, and

L is a condensed polycyclic group including 6 or more fused rings and agroup represented by Chemical Formula 2,

wherein, in Chemical Formula 2,

each of Ar¹ and Ar² are independently one of a substituted orunsubstituted five-membered ring and a substituted or unsubstitutedsix-membered ring,

Ar³ is one of

each of X¹ to X⁴ are independently one of O, S, Se, Te, and NR^(a),

each of R¹, R², R^(a), R^(x), and R^(y) are independently one ofhydrogen, a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₇to C₃₀ arylalkyl group, a substituted or unsubstituted C₁ to C₃₀heteroalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocyclic group, a substituted or unsubstituted C₂ to C₃₀ alkenylgroup, a substituted or unsubstituted C₂ to C₃₀ alkynyl group, a hydroxygroup, a halogen, and a combination thereof,

each of a and b are independently an integer ranging from 1 to 3, and

* is a linking point,

when in Chemical Formula 2, Ar³ is

and a=b=1, the L is a group represented by Chemical Formula 3:

wherein, in Chemical Formula 3,

Ar¹, Ar², X¹ to X⁴, R¹, R² and * are the same as defined in ChemicalFormula 2.

Each of the Ar¹ and Ar² may independently be one of a substituted orunsubstituted benzene ring and a substituted or unsubstitutedheterocyclic group.

Each of the Ar¹ and Ar² may be a substituted or unsubstituted benzenering.

In Chemical Formula 2, a and be may satisfy a=b=1 or a=b=2.

The L may be represented by one of the following compounds of Group 1.

In Group 1,

each of X¹ to X⁴ are independently one of O, S, Se, Te, and NR^(a),

each of R¹ to R¹² and R^(a) are independently one of hydrogen, asubstituted or unsubstituted C₁ to C₃₀ alkyl group, a substituted orunsubstituted C₃ to C₃₀ cycloalkyl group, a substituted or unsubstitutedC₆ to C₃₀ aryl group, a substituted or unsubstituted C₇ to C₃₀ arylalkylgroup, a substituted or unsubstituted C₁ to C₃₀ heteroalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocycloalkyl group, asubstituted or unsubstituted C₂ to C₃₀ alkynyl group, a hydroxy group, ahalogen, and a combination thereof, and

* is a linking point.

Each of the A and B may independently be represented by one of thefollowing compounds of Group 2.

In Group 2,

each of X²¹ to X²³ are independently one of O, S, Se, Te, and NR^(a),

each of R²¹ to R²⁶ and R^(a) are independently one of hydrogen, asubstituted or unsubstituted C₁ to C₃₀ alkyl group, a substituted orunsubstituted C₃ to C₃₀ cycloalkyl group, a substituted or unsubstitutedC₆ to C₃₀ aryl group, a substituted or unsubstituted C₇ to C₃₀ arylalkylgroup, a substituted or unsubstituted C₁ to C₃₀ heteroalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocycloalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocyclic group, a substitutedor unsubstituted C₂ to C₃₀ alkenyl group, a substituted or unsubstitutedC₂ to C₃₀ alkynyl group, a hydroxy group, a halogen, and a combinationthereof, and

* is a linking point.

Each of the Z¹ to Z⁶ may independently be a halogen.

The organic compound may be is represented by one of the followingcompounds of Group 3.

In Group 3,

each of X¹ to X⁴ are independently one of O, S, Se, Te, and NR^(a),

R^(a) is one of hydrogen, a substituted or unsubstituted C₁ to C₃₀ alkylgroup, a substituted or unsubstituted C₃ to C₃₀ cycloalkyl group, asubstituted or unsubstituted C₆ to C₃₀ aryl group, a substituted orunsubstituted C₇ to C₃₀ arylalkyl group, a substituted or unsubstitutedC₁ to C₃₀ heteroalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocyclic group, a substituted or unsubstituted C₂ to C₃₀ alkenylgroup, a substituted or unsubstituted C₂ to C₃₀ alkynyl group, a hydroxygroup, a halogen, and a combination thereof.

According to example embodiments, an organic thin film includes theorganic compound.

According to example embodiments, an electronic device includes theorganic compound.

According to example embodiments, a thin film transistor includes a gateelectrode, an organic semiconductor overlapping the gate electrode, anda source electrode and a drain electrode electrically connected to theorganic semiconductor, wherein the organic semiconductor includes anorganic compound represented by Chemical Formula 1.

According to example embodiments, an electronic device includes the thinfilm transistor.

The electronic device may include one of a solar cell, a liquid crystaldisplay, an organic light emitting device, an electrophoretic device, anorganic photoelectric device, and an organic sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a thin film transistoraccording to example embodiments,

FIG. 2 shows an MALDI-TOF mass analysis data of the compound accordingto Synthesis Example 1.

FIG. 3 shows an MALDI-TOF mass analysis data of the compound accordingto Synthesis Example 2.

FIG. 4 is a graph showing charge mobility of the organic thin filmtransistor according to Example 1.

FIG. 5 is a graph showing charge mobility of the organic thin filmtransistor according to Example 2.

DETAILED DESCRIPTION

Example embodiments will hereinafter be described in detail, and may beeasily performed by those who have common knowledge in the related art.However, this disclosure may be embodied in many different forms and isnot construed as limited to the example embodiments set forth herein.

It should be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers, and/or sections should not be limited by these terms. Theseterms are only used to distinguish one element, component, region,layer, or section from another region, layer, or section. Thus, a firstelement, component, region, layer, or section discussed below could betermed a second element, component, region, layer, or section withoutdeparting from the teachings of example embodiments.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,”“upper,” and the like) may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It should be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” may encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The terminology used herein is for the purpose of describing variousembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“includes,” “including,” “comprises,” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

-   -   Example embodiments are described herein with reference to        cross-sectional illustrations that are schematic illustrations        of idealized embodiments (and intermediate structures) of        example embodiments. As such, variations from the shapes of the        illustrations as a result, for example, of manufacturing        techniques and/or tolerances, are to be expected. Thus, example        embodiments should not be construed as limited to the shapes of        regions illustrated herein but are to include deviations in        shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, including those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

As used herein, when a definition is not otherwise provided, the term‘substituted’ refers to substitution with a halogen (F, Br, Cl, or I), ahydroxy group, an alkoxy group, a nitro group, a cyano group, an aminogroup, an azido group, an amidino group, a hydrazino group, a hydrazonogroup, a carbonyl group, a carbamyl group, a thiol group, an estergroup, a carboxyl group or a salt thereof, a sulfonic acid group or asalt thereof, a phosphoric acid or a salt thereof, a C₁ to C₂₀ alkylgroup, a C₂ to C₂₀ alkenyl group, a C₂ to C₂₀ alkynyl group, a C₆ to C₃₀aryl group, a C₇ to C₃₀ arylalkyl group, a C₁ to C₃₀ alkoxy group, a C₁to C₂₀ heteroalkyl group, a C₃ to C₂₀ heteroarylalkyl group, a C₃ to C₃₀cycloalkyl group, a C₃ to C₁₅ cycloalkenyl group, a C₆ to C₁₅cycloalkynyl group, C₃ to C₃₀ heterocycloalkyl group, and a combinationthereof, instead of hydrogen of a compound.

As used herein, when a definition is not otherwise provided, the term‘hetero’ refers to one including 1 to 3 hetero atoms selected from N, O,S, Se, and P.

Hereinafter, an organic compound according to example embodiments isdescribed.

An organic compound according to example embodiments is represented byChemical Formula 1.

In Chemical Formula 1,

each of A and B are independently one of a substituted or unsubstitutedC₆ to C₃₀ arylene group, a divalent substituted or unsubstituted C₂ toC₃₀ heterocyclic group, and a combination thereof,

each of Z¹ to Z⁶ are independently one of hydrogen, a C₁ to C₁₀haloalkyl group, and a halogen, provided that at least one of Z¹ to Z⁶is one of a C₁ to C₁₀ haloalkyl group and a halogen,

each of n¹ and n² are independently an integer of 0 to 5, and

L is a condensed polycyclic group including a fused ring of six or morerings and a group represented by Chemical Formula 2,

wherein, in Chemical Formula 2,

each of Ar¹ and Ar² are independently one of a substituted orunsubstituted five-membered ring and a substituted or unsubstitutedsix-membered ring,

Ar³ is one of

each of X¹ to X⁴ are independently one of O, S, Se, Te, and NR^(a),

each of R¹, R², R^(a), R^(x), and R^(y) are independently one ofhydrogen, a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₇to C₃₀ arylalkyl group, a substituted or unsubstituted C₁ to C₃₀heteroalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocyclic group, a substituted or unsubstituted C₂ to C₃₀ alkenylgroup, a substituted or unsubstituted C₂ to C₃₀ alkynyl group, a hydroxygroup, a halogen, and a combination thereof,

each of a and b are independently an integer ranging from 1 to 3, and

* is a linking point,

when in Chemical Formula 2, Ar³ is

and a=b=1, the L is a group represented by Chemical Formula 3:

wherein, in Chemical Formula 3,

Ar¹, Ar², X¹ to X⁴, R¹, R² and * are the same as defined in ChemicalFormula 2.

The organic compound is a low molecular weight compound in which L, acondensed polycyclic group including a fused ring of six or more rings,is placed in the core moiety, and halogen is contained at the terminalend, and the core moiety and the terminal end are connected by apredetermined cyclic group. The organic compound may increases theplanarity thereof by appropriately adjusting the number of fused ringsat the core moiety, so that the packing and stacking between moleculesmay be increased. In addition, the organic compound contains halogen atthe terminal end, so the interaction between thermal ends is enhanced byVan der Waals forces between halogens, and also the pi-pi interactionbetween core moieties is enhanced, so as to further improve anintermolecular interaction or an intermolecular space structure.

Each of the Ar¹ and Ar² may independently be one of a substituted orunsubstituted benzene ring and a substituted or unsubstitutedheterocyclic group.

For example, the L is a fused ring of a substituted or unsubstitutedbenzene ring and a substituted or unsubstituted heterocyclic group, andfor example the Ar¹ and Ar² may be a substituted or unsubstitutedbenzene ring.

For example, when the Ar¹ or Ar² is a substituted or unsubstitutedheterocyclic group, Ar¹ or Ar² may be a heterocyclic group including O,S, Se, Te, or NR^(a), wherein the R^(a) is hydrogen, a substituted orunsubstituted C₁ to C₃₀ alkyl group, a substituted or unsubstituted C₃to C₃₀ cycloalkyl group, a substituted or unsubstituted C₆ to C₃₀ arylgroup, a substituted or unsubstituted C₇ to C₃₀ arylalkyl group, asubstituted or unsubstituted C₁ to C₃₀ heteroalkyl group, a substitutedor unsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₂ to C₃₀ heterocyclic group, a substituted orunsubstituted C₂ to C₃₀ alkenyl group, a substituted or unsubstituted C₂to C₃₀ alkynyl group, a hydroxy group, a halogen, or a combinationthereof.

For example, the condensed polycyclic group represented by L may have asymmetric structure, for example a and b may simultaneously be 1 or aand b may simultaneously be 2, but is not limited thereto.

The L may be represented by one of the following compounds of Group 1,but is not limited thereto.

In Group 1,

each of X¹ to X⁴ are independently one of O, S, Se, Te, and NR^(a),

each of R¹ to R¹² and R^(a) are independently one of hydrogen, asubstituted or unsubstituted C₁ to C₃₀ alkyl group, a substituted orunsubstituted C₃ to C₃₀ cycloalkyl group, a substituted or unsubstitutedC₆ to C₃₀ aryl group, a substituted or unsubstituted C₇ to C₃₀ arylalkylgroup, a substituted or unsubstituted C₁ to C₃₀ heteroalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocycloalkyl group, asubstituted or unsubstituted C₂ to C₃₀ alkynyl group, a hydroxy group, ahalogen, and a combination thereof, and

* is a linking point.

As described above, the organic compound contains at least one halogenat the terminal end, and the at least one halogen may be contained inone side terminal end or may be contained in both terminal ends. Forexample, the halogen may be fluorine. For example, in Chemical Formula1, each of Z¹ to Z⁶ may independently be a halogen (e.g., fluorine (F),chlorine (Cl), bromine (Br), or iodine (I)). For example, all Z¹ to Z⁶may be fluorine. For example, in Chemical Formula 1, each of n¹ and n²may independently be an integer of 1 to 5, for example 1 or 2, but isnot limited thereto.

In Chemical Formula 1, A and B may be, for example one of substituted orunsubstituted groups of Group 2, but is not limited thereto.

In Group 2,

each of X²¹ to X²³ are independently one of O, S, Se, Te, and NR^(a),

each of R²¹ to R²⁶ and R^(a) are independently one of hydrogen, asubstituted or unsubstituted C₁ to C₃₀ alkyl group, a substituted orunsubstituted C₃ to C₃₀ cycloalkyl group, a substituted or unsubstitutedC₆ to C₃₀ aryl group, a substituted or unsubstituted C₇ to C₃₀ arylalkylgroup, a substituted or unsubstituted C₁ to C₃₀ heteroalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocycloalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocyclic group, a substitutedor unsubstituted C₂ to C₃₀ alkenyl group, a substituted or unsubstitutedC₂ to C₃₀ alkynyl group, a hydroxy group, a halogen, and a combinationthereof, and

* is a linking point.

The organic compound may be, for example, represented by one of thefollowing compounds of Group 3, but is not limited thereto.

In Group 3,

each of X¹ to X⁴ are independently one of O, S, Se, Te, and NR^(a),

R^(a) is independently one of hydrogen, a substituted or unsubstitutedC₁ to C₃₀ alkyl group, a substituted or unsubstituted C₃ to C₃₀cycloalkyl group, a substituted or unsubstituted C₆ to C₃₀ aryl group, asubstituted or unsubstituted C₇ to C₃₀ arylalkyl group, a substituted orunsubstituted C₁ to C₃₀ heteroalkyl group, a substituted orunsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₂ to C₃₀ heterocyclic group, a substituted orunsubstituted C₂ to C₃₀ alkenyl group, a substituted or unsubstituted C₂to C₃₀ alkynyl group, a hydroxy group, a halogen, and a combinationthereof.

The organic compound may be used for making an organic thin film by adeposition or solution processes. The organic thin film may be appliedto various devices including an organic semiconductor. For example, theorganic compound may be applied to a thin film transistor, and may beapplied as a charge transport layer and/or active layer in an electronicdevice, e.g., a solar cell, a liquid crystal display (LCD), organiclight emitting display device, an electrophoretic device, an organicphotoelectric device, and an organic sensor.

Hereinafter, one example of a thin film transistor including the organiccompound is illustrated referring to drawings.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present.

FIG. 1 is a cross-sectional view showing a thin film transistoraccording to example embodiments.

A gate electrode 124 is formed on a substrate 110 made of a transparentglass, silicon, or plastic. The gate electrode 124 is connected to agate line (not shown) transmitting a data signal. The gate electrode 124may be made of gold (Au), copper (Cu), nickel (Ni), aluminum (Al),molybdenum (Mo), chromium (Cr), tantalum (Ta), titanium (Ti), an alloythereof, or a combination thereof.

A gate insulating layer 140 is formed on the gate electrode 124. Thegate insulating layer 140 may be made of an organic material or aninorganic material, examples of the organic material may include apolyvinyl alcohol-based compound, a polyimide-based compound, apolyacryl-based compound, a polystyrene-based compound, and a dissolublepolymer compound (e.g., benzocyclobutane (BCB), and examples of theinorganic material may include a silicon nitride (SiN_(x)) and a siliconoxide (SiO₂)).

A source electrode 173 and a drain electrode 175 are formed on the gateinsulating layer 140. The source electrode 173 and the drain electrode175 face each other in the center of the gate electrode 124. The sourceelectrode 173 is electrically connected to is connected to a data line(not shown) transmitting a data signal. The source electrode 173 anddrain electrode 175 may be made of, for example, gold (Au), copper (Cu),nickel (Ni), aluminum (Al), molybdenum (Mo), chromium (Cr), tantalum(Ta), titanium (Ti), an alloy thereof, or a combination thereof.

An organic semiconductor 154 is formed on the source electrode 173 andthe drain electrode 175. The organic semiconductor 154 may be made ofthe organic compound. The organic semiconductor 154 may be formed bypreparing the organic compound in a form of a solution and a solutionprocess, for example spin coating, slit coating or inkjet printing.However, the organic semiconductor 154 may be formed by a dry process,e.g., deposition of the organic compound.

Herein, as one example of a thin film transistor, a thin film transistorhaving a bottom gate structure is illustrated, but is not limitedthereto, and may be applied to a thin film transistor having a top gatestructure in the same manner.

The thin film transistor may be applied as a switch or driving device ofvarious electronic devices, and the electronic device may include, forexample a liquid crystal display (LCD), an organic light emittingdisplay device, an electrophoretic display device, an organicphotoelectric device, and an organic sensor.

Hereinafter, the present disclosure is illustrated in more detail withreference to examples. However, these are examples, and the presentdisclosure is not limited thereto.

SYNTHESIS OF ORGANIC COMPOUNDS Synthesis Example 1

(Synthesis of Compound P1)

8 g (33 mmol) of 2,4-dibrom thiophene, 7.52 g (39.6 mmol) of4-(trifluoromethyl)boronic acid, 8.66 g (66 mmol) of potassiumcarbonate, 0.953 g (0.825 mmol) of tetrakis(triphenylphosphine)palladium(0), 640 ml of THF, and 40 ml of water are placed in 2000 ml two-neckflask and refluxed at 65° C. for 12 hours. Then the reaction iscompleted by water and chloroform and worked-up. Subsequently, it ispurified by hexane using a column chromatography to provide Compound P1.(yield: 71%)

(Synthesis of Compound P2)

0.515 g (1.68 mmol) of Compound P1 is placed in a 100 ml one-neck flaskand dissolved in 20 ml of THF. After the temperature is dropped to −78°C., 0.84 ml (1.68 mmol) of LDA is added thereto. Then 0.15 g (0.765mmol) of thieno[3,2-b]thiophene-2,5-dicarbaldehyde is added thereto.After 12 hours, the reaction is completed by sodium hydrogen carbonateand worked-up with chloroform. Subsequently, it is recrystallized usingchloroform to provide Compound P2. (yield: 46%)

(Synthesis of Compound P3)

0.38 g (0.468 mmol) of Compound P2, 0.44 g (3.52 mmol) of sodiumcyanoborohydride (NaCNBH₃) and zinc iodide (ZnI₂) are placed in 250 ml2-neck flask. 70 ml of 1,2 dichloroethane is added thereto and refluxedat a temperature of 40° C. and left to stand overnight. 50 ml of wateris slowly poured into a reaction vessel and slowly added with 1N HCl tocomplete the reaction. After the work-up by chloroform, it is purifiedby precipitation using methanol to provide Compound P3 (yield: 80%).

(Synthesis of Compound P4)

1.0 g of Compound P3, 0.6 g of CuCN and 20 ml of NMP are placed in 50 mlvial and reacted in a microwave reactor at a temperature of 180° C. for1 hour and 30 minutes. Then the reaction is completed by 1 N HClsolution and worked-up using DCM. Then it is purified by precipitationusing ethyl acetate to provide Compound P4 (yield: 85%).

(Synthesis of Compound P5)

1.82 g (2.72 mmol) of Compound P4 is dissolved in 200 ml of DCM andcooled down to a temperature of −10° C. Then 8.5 ml (8.16 mmol) ofDIBAL-H is slowly added thereto. After 2 hours at −10° C., 1N HCl (MeOH(3): H₂O (1)) is slowly added thereto. Then the temperature is slowlyincreased up to a room temperature. Then an organic layer is isolatedusing water and DCM. It is separated and purified by a columnchromatography using chloroform to provide Compound P5. (yield: 39%)

(Synthesis of Compound P6)

1.0 g of compound P5, 1.0 g of Amberlyst 15 (manufactured bySigma-Aldrich), and 20 ml of 1,2-Dichorobenzene are added and reacted ina microwave reactor at 120° C. for 14 hours. After the temperature isdropped to a room temperature, it is separated and purified by decantingthe same using ethyl acetate to provide Compound P6. (yield: 50%)

Subsequently, the real structure of the final compound (Compound P6)obtained from Synthesis Example 1 is confirmed by a MALDI-TOF massanalysis.

FIG. 2 shows an MALDI-TOF mass analysis data of the final compoundaccording to Synthesis Example 1 (m/z=639.898). Referring to FIG. 2, thecompound of Synthesis Example is actually obtained.

Synthesis Example 2

(Synthesis of Compound P2′)

0.5 g (2.63 mmol) of benzo[1,2-b:4,5-b′]dithiophene is dissolved in 30ml of THF, and after cooling the temperature up to −78° C. under thenitrogen atmosphere, a lithium diisopropylamine (LDA) solution (2.0 M,3.0 ml, 5.8 mmol, 2.2 equiv.) is carefully added thereto. Then whenreaching to 0° C., the temperature is dropped again to −78° C., andanhydrous dimethylformamide (0.6 ml, excess) is added thereto. Whenreaching the room temperature, 1N HCl solution is added thereto andstirred for 20 minutes. Then pH is neutralized by adding NaHCO₃ having a1N concentration. Then the organic layer is extracted bydichloromethane, and moisture is removed using MgSO₄ and dried. Then itis purified using column chromatography to provide Compound P2′ (yield:80%).

(Synthesis of Compound P3′)

1.35 g (4.4 mmol) of Compound P1 obtained from Synthesis Example 1 isplaced in 100 ml one-neck flask and dissolved in 30 ml of THF. Thenafter the temperature is dropped to −78° C., 2.2 ml (4.4 mmol) of LDA isadded thereto. Then 0.5 g (2.0 mmol) ofbenzo[1,2-b:4,5-b′]dithiophene-dicarbaldehyde is added thereto. After 12hours, the reaction is completed by sodium hydrogen carbonate andworked-up by chloroform. Then it is recrystallized by chloroform toprovide Compound P3′ (yield: 65%).

(Synthesis of Compound P4′)

3.8 g (4.42 mmol) of P3′, 4.44 g (70.72 mmol) of sodium cyanoborohydride(NaCNBH₃), and 5.64 g (17.68 mmol) of zinc iodide (ZnI₂) are placed in1000 ml two-neck flask. 600 ml of 1,2 dichloroethane is added theretoand refluxed at a temperature of 40° C. and left to stand overnight. 50ml of water is slowly poured to the reaction vessel, and then 1N HCl isslowly added to complete the reaction. After the work-up by chloroform,it is purified by precipitation using methanol to provide Compound P4′(yield: 80%).

(Synthesis of Compound P5′)

1.0 g of P4′ and 0.45 g of CuCN, 20 ml of NMP are placed into 50 ml vialand reacted in a microwave reactor at a temperature of 180° C. for 1hour 30 minutes. Then the reaction is completed by 1 N HCl solution andworked-up using DCM. Then the precipitation is separated using ethylacetate to provide Compound P5′ (yield: 60%).

(Synthesis of Compound P6′)

1.0 g (1.38 mmol) of P5′ is dissolved in 120 ml of DCM and cooled downto a temperature of −10° C. Then 4.13 ml (4.13 mmol) of DIBAL-H isslowly added thereto. After 2 hours at −10° C., 1 N HCl (MeOH (3): H₂O(1)) is slowly added thereto. Then the temperature is slowly increasedup to a room temperature. Then the organic layer is separated usingwater and DCM. It is purified by a column chromatography usingchloroform to provide Compound P6′ (yield: 50%).

(Synthesis of Compound P7′)

1.0 g of P6′ and 1.0 g of Amberlyst 15, 20 ml of 1,2-dichorobenzene areplaced in a vial and reacted in a microwave reactor at 120° C. for 10hours. After the temperature is dropped to a room temperature, it isseparated and purified by decanting the same using ethyl acetate toprovide Compound P7′ (yield: 50%).

Subsequently, the real structure of the final compound (Compound P7′)obtained from Synthesis Example 2 is confirmed by MALDI-TOF massanalysis.

FIG. 3 shows an MALDI-TOF mass analysis data of the final compoundaccording to Synthesis Example 2 (m/z=690.017). Referring to FIG. 3, thecompound of Synthesis Example is actually obtained.

Manufacture of Organic Thin Film Transistor

Example 1

First, a silicon wafer substrate covered with a cleaned SiO₂ in 3000 Åis exposed to O₂ plasma and then dipped in an octadecyltrichloro silanesolution, which is diluted in hexane at a concentration of 10 mM, tochange the surface to hydrophobicity. Subsequently, the organic compoundobtained Synthesis Example 1 is deposited on a substrate in a thicknessof 700 Å according to the vacuum vapor deposition while the temperatureof substrate is changed from a room temperature to 200° C. Subsequently,source and drain electrodes are deposited by Au in a thickness of 1000 Åusing a shadow mask to provide an organic thin film transistor.

Example 2

An organic thin film transistor is fabricated in accordance with thesame procedure as in Example 1, except that the organic compoundobtained from Synthesis Example 2 is used instead of the organiccompound obtained from Synthesis Example 1.

Evaluation

A charge mobility of the organic thin film transistor according toExample 1 is calculated.

A graph with variations of (I_(SD))^(1/2) and V_(GS) is obtained fromthe saturation region current formula, and a charge mobility of theorganic thin film transistor is obtained from the slope thereof:

$I_{SD} = {\frac{{WC}_{0}}{2L}{\mu\left( {V_{GS} - V_{T}} \right)}^{2}}$$\sqrt{I_{SD}} = {\sqrt{\frac{\mu\; C_{0}W}{2L}}\left( {V_{GS} - V_{T}} \right)}$${slope} = \sqrt{\frac{\mu\; C_{0}W}{2L}}$$\mu_{FET} = {({slope})^{2}\frac{2L}{C_{0}W}}$

In Equation, I_(SD) is a source-drain current; μ or μ_(FET) is a chargemobility; C₀ is a capacitance of gate insulating layer; W is a channelwidth; L is a channel length; V_(GS) is a gate voltage; V_(T) is athreshold voltage.

An off-state leakage current (I_(off)), which is a current flowing inoff-state, is determined by the minimum current at the off-state in thecurrent ratio. The current on-off ratio (I_(on)/I_(off)) is obtained bya ratio of the maximum current value at on-state to the minimum currentvalue at off-state.

The results are shown in FIGS. 4 and 5 and Table 1.

FIG. 4 is a graph showing charge mobility of the organic thin filmtransistor according to Example 1 and FIG. 5 is a graph showing chargemobility of the organic thin film transistor according to Example 2.

TABLE 1 Charge mobility Maximum current Current on-off ratio (cm²/Vs)value in on state (A) (I_(on)/I_(off)) Example 1 11.48 6.66 × 10⁻⁴ 3.00× 10⁹ Example 2 14.63 3.81 × 10⁻⁴ 3.50 × 10⁹

Referring to FIGS. 4 and 5 and Table 1, the thin film transistoraccording to Example 1 has charge mobility of greater than or equal toabout 11 cm²/Vs and current on-off ratio of greater than or equal toabout 10⁹, thereby having improved characteristics

While this disclosure has been described in connection with what ispresently considered to be practical example embodiments, it is to beunderstood that the inventive concepts are not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. An organic compound represented by ChemicalFormula 1:

wherein in Chemical Formula 1, each of A and B are independently one ofa substituted or unsubstituted C₆ to C₃₀ arylene group, a divalentsubstituted or unsubstituted C₂ to C₃₀ heterocyclic group, and acombination thereof, each of Z¹ to Z⁶ are independently one of hydrogen,a C₁ to C₁₀ haloalkyl group, and a halogen, provided that at least oneof Z¹ to Z⁶ is one of a C₁ to C₁₀ haloalkyl group and a halogen, each ofn¹ and n² are independently an integer of 0 to 5, and L is a condensedpolycyclic group including 6 or more fused rings and a group representedby Chemical Formula 2,

wherein, in Chemical Formula 2, each of Ar¹ and Ar² are independentlyone of a substituted or unsubstituted five-membered ring and asubstituted or unsubstituted six-membered ring, Ar³ is one of

each of X¹ to X² are independently one of O, Se, Te, and NR^(a), each ofX³ to X⁴ are independently one of O, S, Se, Te, and NR^(a), each of R¹,R², R^(a), R^(x) and R^(y) are independently one of hydrogen, asubstituted or unsubstituted C₁ to C₃₀ alkyl group, a substituted orunsubstituted C₃ to C₃₀ cycloalkyl group, a substituted or unsubstitutedC₆ to C₃₀ aryl group, a substituted or unsubstituted C₇ to C₃₀ arylalkylgroup, a substituted or unsubstituted C₁ to C₃₀ heteroalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocycloalkyl group, asubstituted or unsubstituted C₂ to C₃₀ heterocyclic group, a substitutedor unsubstituted C₂ to C₃₀ lalkenyl group, a substituted orunsubstituted C₂ to C₃₀ alkynyl group, a hydroxy group, a halogen, and acombination thereof, each of a and b are independently an integerranging from 1 to 3, and * is a linking point, when in Chemical Formula2, Ar³ is

 and a=b=1, the L is a group represented by Chemical Formula 3:

wherein, in Chemical Formula 3, Ar¹, Ar², X¹ to X⁴, R¹, R² and * are thesame as defined in Chemical Formula
 2. 2. The organic compound of claim1, wherein each of the Ar¹ and Ar² groups are independently one of asubstituted or unsubstituted benzene ring and a substituted orunsubstituted heterocyclic group.
 3. The organic compound of claim 1,wherein each of the Ar¹ and Ar² groups are a substituted orunsubstituted benzene ring.
 4. The organic compound of claim 3, whereina and b satisfy one of a=b=1 and a=b=2.
 5. The organic compound of claim1, wherein the L is represented by one of the following compounds ofGroup 1:

wherein, in Group 1, each of X¹ to X² are independently one of O, Se,Te, and NR^(a), each of X³ to X⁴ are independently one of O, S, Se, Te,and NR^(a), each of R¹ to R¹² and R^(a) are independently one ofhydrogen, a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₇to C₃₀ arylalkyl group, a substituted or unsubstituted C₁ to C₃₀heteroalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocyclic group, a substituted or unsubstituted C₂ to C₃₀ alkenylgroup, a substituted or unsubstituted C₂ to C₃₀ alkynyl group, a hydroxygroup, a halogen, and a combination thereof, and * is a linking point.6. The organic compound of claim 1, wherein each of A and B isrepresented by one of the following compounds of Group 2:

wherein, in Group 2, each of X²¹ to X²³ are independently one of O S,Se, Te, and NR^(a), each of R²¹ to R²⁶ and R^(a) are independently oneof hydrogen, a substituted or unsubstituted C₁ to C₃₀ alkyl group, asubstituted or unsubstituted C₃ to C₃₀ cycloalkyl group, a substitutedor unsubstituted C₆ to C₃₀ aryl group, a substituted or unsubstituted C₇to C₃₀ arylalkyl group, a substituted or unsubstituted C₁ to C₃₀heteroalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocycloalkyl group, a substituted or unsubstituted C₂ to C₃₀heterocyclic , group, a substituted or unsubstituted C₂ to C₃₀ alkenylgroup, a substituted or unsubstituted C₂ to C₃₀ alkynyl group, a hydroxygroup, a halogen, and a combination thereof, and * is a linking point.7. The organic compound of claim 1, wherein each of the Z¹ to Z⁶ groupsare independently a halogen.
 8. The organic compound of claim 1, whereinthe organic compound is represented by one of the following compounds ofGroup 3:

wherein, in Group 3, each of X¹ to X² are independently one of O, Se,Te, and NR^(a), each of X³ to X⁴ are independently one of O, S, Se, Te,and NR^(a), R^(a) is one of hydrogen, a substituted or unsubstituted C₁to C₃₀ alkyl group, a substituted or unsubstituted C₃ to C₃₀ cycloalkylgroup, a substituted or unsubstituted C₆ to C₃₀ aryl group, asubstituted or unsubstituted C₇ to C₃₀ arylalkyl group, a substituted orunsubstituted C₁ to C₃₀ heteroalkyl group, a substituted orunsubstituted C₂ to C₃₀ heterocycloalkyl group, a substituted orunsubstituted C₂ to C₃₀ heterocyclic group, a substituted orunsubstituted C₂ to C₃₀ alkenyl group, a substituted or unsubstituted C₂to C₃₀ alkynyl group, a hydroxy group, a halogen, and a combinationthereof.
 9. An organic thin film comprising the organic compound ofclaim
 1. 10. A thin film transistor comprising: a gate electrode; anorganic semiconductor overlapping the gate electrode, the organicsemiconductor including the organic compound of claim 1; and a sourceelectrode and a drain electrode electrically connected to the organicsemiconductor.
 11. An electronic device comprising the thin filmtransistor of claim
 10. 12. The electronic device of claim 11, whereinthe electronic device includes one of a solar cell, a liquid crystaldisplay, an organic light emitting device, an electrophoretic device, anorganic photoelectric device, and an organic sensor.
 13. An electronicdevice comprising the organic thin film of claim 9.